The name of the virus is derived from the following message found inside it.
NEWS FLASH!! Your system has been infected with the incurable decay of LEPROSY 1.00, a virus invented by PCM2 in June of 1990. Good luck!
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
Another variant is known, where the message has been changed to:
ATTENTION! Your computer has been afflicted with the incurable decay that is the fate wrought by Leprosy Strain B, a virus employing Cybernetic Mutation Technology(tm) and invented by PCM2 08/90.
Infected programs will either display this message or
Program too big to fit in memory
Leprosy is a 666 byte overwriting virus, and infected programs must be deleted, as there is no way to remove the virus. The only thing which is remarkable about it is the fact that the virus is written in C.
Variant:Plague, Viper, Busted
Plague is a slightly shorter variant, 591 bytes long. It contains the following text:
Autopsy indicates the cause of death was THE PLAGUE Dedicated to the dudes at SHHS VIVE LE SHE-MAN!
Viper is related, but uses a slightly different encryption method and is 840 bytes long. Busted is yet another variant, which contains the text
"Busted!"
Variant:Xabaras
This variant has been changed quite a bit, probably in order to avoid detection by some anti-virus program. It is also longer - 1972 bytes.
Variant:Leprosy-C, Leprosy-D, Scribble, Seneca, Surfer
Other variants, just as non-interesting as the previous ones.